- #1
PhysicStud01
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- Homework Statement
- Why does the graph have this shape?
- Relevant Equations
- area under the graph gives the change in momentum
Answer is C.
Is Ball Bouncing on a Surface a Simple Harmonic Motion?
In summary, the conversation discusses the shape of a force extension graph and how it relates to the behavior of a rubber ball and table surface in contact. The force increases at a decreasing rate, reaches a maximum, and then decreases at an increasing rate. This shape is due to the elastic deformation of the ball and table surface and the model used to describe it. The curve should be continuous and can be approximated as a straight line, but in reality it is likely to follow a sine wave pattern.
Answer is C.
- #2
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..., and your question is...?PhysicStud01 said:
- #3
PhysicStud01
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why is the shape of the force extension graph this way?
area gives change in momentum.
but the gradient does not represent any physical quantity?
why does the force increase at a decreasing rate, then decrease at an increasing rate?
area gives change in momentum.
but the gradient does not represent any physical quantity?
why does the force increase at a decreasing rate, then decrease at an increasing rate?
- #4
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Step at a time: what is happening?
- #5
PhysicStud01
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the ball has an initial velocity down.
this is reduced to zero, then increase upwards.
but does the force change this way? is it not constant? and why with this gradient?
this is reduced to zero, then increase upwards.
but does the force change this way? is it not constant? and why with this gradient?
- #6
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The force is zero just before contact is made, it is also zero immediately after contact is lost and is non-zero in between. Which of the 4 graphs best shows this?
- #7
PhysicStud01
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thanks, I had already understood this one.kuruman said:
but during the contact, why does the force behave this way?
- #8
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How else can it behave if it is zero at the beginning and the end of the time interval? It has to reach a maximum in between. The idea is that the rubber ball and the table surface deform elastically while they are in contact. The force that one exerts on the other increases as the deformation increases, it is maximum at maximum deformation and decreases as the deformation decreases. Now if you are asking about the specific shape of the curve, that depends on the model used to describe the deformation, however all models will have the same general feature which distinguishes (c) from all the other answers.PhysicStud01 said:
- #9
PhysicStud01
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so, it could be straight lines too? as long as it starts from zero, reach a maximum, then decreases to zero again?kuruman said:
- #10
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It could be as an approximation. Nature almost always abhors sharp corners which means that the slope of the F vs. t curve should be continuous at all points.
- #11
PhysicStud01
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ok, thanks
- #12
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The ball is elastic, so to a first approximation it should be SHM. That makes it the positive half of a sine wave.PhysicStud01 said:
FAQ: Is Ball Bouncing on a Surface a Simple Harmonic Motion?
What factors affect how high a ball bounces off a surface?
The height of a ball's bounce is affected by several factors, including the material and texture of the surface, the weight and elasticity of the ball, and the angle at which it hits the surface. The surface's temperature and air pressure can also play a role.
Why does a ball bounce higher on some surfaces than others?
The height of a ball's bounce is determined by the amount of energy it retains after hitting a surface. Softer surfaces, like grass or sand, absorb more of the ball's energy, resulting in a lower bounce. Harder surfaces, like concrete or wood, reflect more of the energy, causing the ball to bounce higher.
What is the relationship between the height of a ball's bounce and the force applied?
The height of a ball's bounce is directly related to the force applied when it hits a surface. The greater the force, the higher the bounce. This is because more force means more energy is transferred to the ball, allowing it to bounce higher.
Why does a ball bounce back after hitting a surface?
When a ball hits a surface, the atoms in the surface's material are compressed, storing potential energy. As the ball begins to bounce back, the potential energy is converted into kinetic energy, causing the ball to accelerate back up. The elasticity of the ball also plays a role in how much energy is retained and how high it bounces.
Can the height of a ball's bounce be predicted?
The height of a ball's bounce can be predicted using the coefficient of restitution, which is a measure of how much energy is retained after a collision. This value varies depending on the materials involved and can be used to calculate the height of a ball's bounce on different surfaces.